@article{GDZPPN002226766, title = {Old and New on S1(2).}, journal = {Manuscripta mathematica}, volume = {55}, year = {1986}, pages = {17-52}, zbl = {0605.22004}, url = {http://dml.mathdoc.fr/item/GDZPPN002226766} }
Hofmann, Karl H.; Hilgert, Joachim. Old and New on S1(2).. Manuscripta mathematica, Tome 55 (1986) pp. 17-52. http://gdmltest.u-ga.fr/item/GDZPPN002226766/